1Heat oven to 350ºF. In 2-quart saucepan, heat milk and margarine over medium heat until margarine is melted and milk is hot.
2In large bowl, mix sugar, cinnamon, salt, egg and egg whites with wire whisk until well blended. Stir in bread cubes and raisins. Stir in milk mixture. Pour into ungreased 1 1/2-quart casserole or 8-inch square (2-quart) glass baking dish. Place casserole in 13x9-inch pan; pour boiling water into pan until 1 inch deep.
3Bake uncovered 40 to 45 minutes or until knife inserted 1 inch from edge of casserole comes out clean.
4In small bowl, mix caramel sauce and bourbon until smooth. Serve sauce over warm bread pudding. Store in refrigerator.